French make cars from flax

published: October 11th, 2009
author: Ray Hutton
source: The Sunday Times
website: http://www.timesonline.co.uk

Welcome to the bio-car. PSA, the French automotive group that makes Peugeots and Citroëns, has started using components made from natural materials — radiator caps and side mirror mountings that contain hemp instead of glassfibre; parcel shelves that are moulded in a plastic made from wood chippings; and inner door panels that are 50% flax.

The components are the fruit of PSA's Green Materials Plan, set up last year. Its target is a six-fold increase in natural and renewable materials used in all its vehicles by 2015.

The programme, which covers all models in development, will bring weight and cost savings as well as a reduction in energy use and carbondioxide emissions, and the conservation of non-renewable resources.

The plan has three elements — recycled materials, natural fibres and bio-polymers. PSA's plan is to replace plastics derived from oil. The motor industry takes 7% of the world's oil-based plastic production — which accounts in total for 4% of all oil use.

Another drive is on recycling. The steel of the car body and other metals are already close to 100% recycled but the polypropylene used to make bumpers can be shredded when the car is scrapped and the resulting material made into new mouldings.

Plastic drinks bottles and their caps are granulated and combined with a small proportion of glassfibre to produce windscreen wiper arms and mudflaps for wheelarches. Women's tights are suitable for reprocessing and blending with glassfibre to make non-structural hard plastic parts under the bonnet.

These processes are already commonplace in the motor industry and its component suppliers and so is the use of plant material to form felt for sound-proofing. Research engineers at Peugeot Citroën are now concentrating on plastics, where natural materials can replace synthetic fibres.

The Peugeot 207's injection-moulded mirror structure and the cooling system cap that will eventually be used in all the company's vehicles are 30% hemp.

The introduction of materials made entirely without mineral oil is at an early stage and yet bio-polymers are actually a return to an old idea, from the early days of plastics.

The Model T Ford, made between 1908 and 1927, had some parts made from soya polymers and, in 1941, Henry Ford demonstrated the strength of the material by taking a sledgehammer to a prototype car with plastic body panels. The car survived unscathed but production plans were scrapped.